AIM: This prospective pilot study evaluated urinary interferon-γ-induced protein-10 (IP-10)/creatinine and tumour necrosis factor-related apoptosis-inducing ligand (TRAIL)/creatinine ratios as non-invasive biomarkers for distinguishing bacterial from viral infections and assessing disease severity in febrile children. METHODS: The study involved 85 febrile children and 29 healthy controls, measuring urinary IP-10/creatinine and TRAIL/creatinine ratios to determine their diagnostic utility. RESULTS: Both ratios were significantly elevated in infected patients compared to controls. The IP-10/creatinine ratio effectively assessed disease severity in the overall cohort and subgroups (AUC: 0.7324, 0.7192, 0.7277
p <
0.05). Serum C-reactive protein showed limited discriminatory ability in viral infections (AUC = 0.5385, p = 0.7257). Differentiation between bacterial and viral infections using IP-10/creatinine approached significance (p = 0.082). No significant differences in biomarker levels were observed across pathogens. CONCLUSION: The urinary IP-10/creatinine ratio shows promise as a biomarker for assessing paediatric infection severity, particularly when traditional markers are less effective. Larger studies are needed to validate these results and improve its discriminatory accuracy in clinical practice.